10.5061/DRYAD.R5J0S3N
Grainger, Tess Nahanni
University of Toronto
Letten, Andrew D.
Stanford University
Gilbert, Benjamin
University of Toronto
Fukami, Tadashi
Stanford University
Data from: Applying modern coexistence theory to priority effects
Dryad
dataset
2019
Fitness difference
Stabilizing difference
priority effects
invasion criterion
Niche difference
Metschnikowia rancensis
Metschnikowia gruessii
Metschnikowia reukaufii
Modern coexistence theory
Toronto
National Science Foundation
https://ror.org/021nxhr62
1737758
2019-03-19T20:54:11Z
2019-03-19T20:54:11Z
en
https://doi.org/10.1073/pnas.1803122116
39774 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Modern coexistence theory is increasingly used to explain how differences
between competing species lead to coexistence versus competitive
exclusion. Although research testing this theory has focused on
deterministic cases of competitive exclusion, in which the same species
always wins, mounting evidence suggests that competitive exclusion is
often historically contingent, such that whichever species happens to
arrive first excludes the other. Coexistence theory predicts that
historically contingent exclusion, known as priority effects, will occur
when large destabilizing differences (positive frequency-dependent growth
rates of competitors), combined with small fitness differences
(differences in competitors’ intrinsic growth rates and sensitivity to
competition), create conditions under which neither species can invade an
established population of its competitor. Here we extend the empirical
application of modern coexistence theory to determine the conditions that
promote priority effects. We conducted pairwise invasion tests with four
strains of nectar-colonizing yeasts to determine how the destabilizing and
fitness differences that drive priority effects are altered by two abiotic
factors characterizing the nectar environment: sugar concentration and pH.
We found that higher sugar concentrations increased the likelihood of
priority effects by reducing fitness differences between competing
species. In contrast, higher pH did not change the likelihood of priority
effects, but instead made competition more neutral by bringing both
fitness differences and destabilizing differences closer to zero. This
study demonstrates how the empirical partitioning of priority effects into
fitness and destabilizing components can elucidate the pathways through
which environmental conditions shape competitive interactions.
Data from Grainger et al. 2019 PNASDensities of four yeast species when
grown in monoculture (densities measured at 0h, 48h and 96h) and when
invading each of four competitors (densities measured at 48h and 96h).
Canada